Academic literature on the topic 'SEM contours'

We have developed a novel approach for quantifying the microstructure of granular thin films using digital image processing and analysis. In the past, conventional scanning electron microscopy of thin films has generated qualitative information on the surface topography and film microstructure. However, when coupled to digital image analysis, the amount or degree of surface contours (i.e., granularity) in SEM micrographs can be quantified in a rapid and reproducible manner. Briefly, SEM micrographs are digitized and the edge boundaries on the film surface are enhanced by a gradient filter; granularity is then quantified by calculating the %AREA covered by the edges with respect to the entire field. Objects of a particular shape, such as phase impurity particles, can be selectively deleted from the image using a specific sequence of shape analysis algorithms and parameter values. In this manner, the contributions of edges from the phase impurity particles is minimized in the final measurement of real surface contours. Statistical analysis of the data yields quantitative information concerning variations in microdomains within single thin films and can detect statistically significant differences among samples. This method is being used in the characterization of the microstructure of superconducting thin films for optimization of their electrical and magnetic properties.

RésuméConvoquant le cadre théorique de la sémiotique (post-)greimassienne, cette contribution se propose de cibler quelques-unes des étapes ayant marqué la réflexion sur l’énonciation depuis les années 1970–1980, avant d’esquisser les contours d’une sémiotique de l’énonciation comme pratique située. Ainsi, après avoir rappelé que la théorie de l’énonciation « énoncée » (Greimas et Courtés 1979) invite à repérer les marques laissées dans le texte par l’énonciation, qui est présupposée, virtuelle et hypothétique, nous visons à rendre compte de la dynamique de la constitution du texte (textualisation) en mettant l’accent, d’une part, sur l’énonciation « vivante » (Fontanille 2003 [1998] ; cf. la conversion de la marque en trace) et, d’autre part, sur le geste énonciatif d’une instance sensible pourvue d’une corporalité (cf. la conversion de la marque en empreinte, Fontanille 2011). Enfin, une sémiotique de l’énonciation comme acte ou pratique nous conduit à prendre en considération d’autres strates du parcours de l’expression (Fontanille 2008) que celle du texte, en particulier celle du support-objet. L’accent est également mis sur l’environnement (le cadre institutionnel, socioéconomique et culturel). Dans ce contexte, nous cherchons à évaluer la portée et la pertinence du concept de dispositif.

In order to get direct information on the relationships between the structural and electrical properties of interfaces, we developed in situ experiments in TEM-STEM and SEM for the characterization of the local behaviour of majority and minority carriers. In particular, we described here our new technique for local determination of interfacial potential barriers in electronic ceramics. This information is completed by voltage contrast imaging in SEM at 1 kV which enables a full map of the distribution of these interfacial barriers to be obtained.The TEM experiment is schematized in fig. 1. A tungsten microelectrode (100 nm diameter) can be micromanipulated in situ and gently set down on the TEM sample. The contact between the microelectrode and the sample is shown sharply by the modification of extinction contours in each adjacent grain (Fig. 2ab).

This work presents an image processing procedure for characterization of porosity and heterogeneity of fully hydrated hydrogels based on the analysis of cryogenic scanning electron microscopy (cryo-SEM) images. An algorithm consisting of different filtering, morphological transformation, and thresholding steps to denoise the image whilst emphasizing the hydrogel fibres edges for extracting the pores features is explained. Finally, the information of hydrogel porosity and heterogeneity is presented in form of pore size distribution, spatial contours maps and kernel density dot plots. The obtained results reveal that a non-parametric kernel density plot effectively determines the spatial heterogeneity and porosity of the hydrogel.